Discovery and analysis<\/strong><\/h2>The Richat Structure is located near the town of Ouadane in the Adrar Region of Mauritania.<\/p>
Locals have known about it for centuries, but no western geologist visited the region\u00a0until the 1930s.<\/p>
At that time, the Richat Structure was believed to be an impact crater.<\/p>
That\u2019s understandable: it looks like one, with its raised outer lip and sunken centre.<\/p>
And there are three other \u201ccrateriform or circular irregularities\u201d (in the words of French naturalist Theodore Monod, who led an expedition to the region in 1952) nearby that were formed as a result of an asteroid<\/a> or meteor impact.<\/p>Further studies revealed the Eye of the Sahara isn\u2019t an impact structure, but has resulted from a combination of different geological, volcanic and meteorological processes.<\/p>![\"Photo](\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2024\/07\/richat-structure.jpg\")
Photo of the Richat Structure, or the Eye of the Sahara, in Mauritania, captured from the International Space Station by astronaut Nick Hague in Septemebr 2019. Click image to expand. Credit: NASA<\/figcaption><\/figure>How the Richat Structure formed<\/strong><\/h2>Stand in the Sahara \u2013 in fact, stand most places on Earth \u2013 and beneath your feet are layers (strata) of different kinds of sedimentary rock.<\/p>
In the case of the Richat Structure, volcanic magma has at some point in the distant past intruded into these layers, causing them to bulge upwards and form a dome shape.<\/p>
This dome became subject to erosion by wind and, as this is the Sahara, vast quantities of sand carried by that wind.<\/p>
The domed shape exposes different layers of sedimentary rock in different places, and some rocks erode more quickly than others.<\/p>![\"Image](\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2024\/07\/Richat_structure_Mauritania.jpg\")
Image of the Richat Structure captured on 23 November 2010 by the Advanced Visible and Near Infrared Radiometer on Japan\u2019s ALOS satellite. Click image to expand.\u00a0Credit: ESA\/JAXA<\/figcaption><\/figure>This transformed the dome into a series of circular ridges of different heights that look, from above, like a bull\u2019s eye or target.<\/p>
Or, as discussed, an impact crater!<\/p>
Further studies revealed the Eye of the Sahara isn\u2019t an impact structure, but has resulted from a combination of different geological, volcanic and meteorological processes.<\/p> Stand in the Sahara \u2013 in fact, stand most places on Earth \u2013 and beneath your feet are layers (strata) of different kinds of sedimentary rock.<\/p> In the case of the Richat Structure, volcanic magma has at some point in the distant past intruded into these layers, causing them to bulge upwards and form a dome shape.<\/p> This dome became subject to erosion by wind and, as this is the Sahara, vast quantities of sand carried by that wind.<\/p> The domed shape exposes different layers of sedimentary rock in different places, and some rocks erode more quickly than others.<\/p> This transformed the dome into a series of circular ridges of different heights that look, from above, like a bull\u2019s eye or target.<\/p> Or, as discussed, an impact crater!<\/p>How the Richat Structure formed<\/strong><\/h2>